4-Bromo-2-(4-chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl)pyrrole-3-ca rbonitrile (hereinafter referred to as chlorfenapyr), which is an active ingredient of the insecticidal and miticidal composition of the invention, is known to be effective against insects such as Hemiptera pests such as leafhoppers (Dolto cephalidae), Lepidoptera pests such as diamond back moth (Plutella xylostella), common cutworm (Spodoptera litura) and apple leafminer (Phyllonorycter ringoniella) and Thysanoptera pests such as Thrips palmi and yellow tea thrips (Spirtothrips dorsalis) and agrohorticultural pests such as mites such as two-spotted spider mite (Tetranychus urticae koch). Kanzawa spider mite (Tetranychus kanzawai kishida) and Aculops pelekassi [Japanese Laid-open (Kokai) Patent Publication No. 104042/89].
The second active ingredient of the insecticidal and miticidal composition of the invention includes at least one of the carbamate-type compounds which are known to be effective insecticidal agents against agricultural pests such as Hemiptera, Lepidoptera and Coleoptera insects and mites.
Although insecticidal and miticidal agents have been developed in order to control various pests such as agrohorticultural pests or hygienic pests and in practice have been used as a single or a mixed agent, pests which have acquired resistance against various agents have been appearing as a result or the repeated use of these agents.
In particular, important economic pests in agrohorticulture such as spider mites (Tetranychidae), which have a propensity to easily develop resistance against pesticidal agents due to their ability to deposit large numbers of eggs and produce large numbers of generations which, themselves, require only a few days for development are of great concern. Resistance development in this pest family is also favored by a high mutation rate and frequent inbreeding, due to minimal migration. For these reasons, two-spotted spider mite (Tetranychus urticae koch), Kanzawa spider mite (Tetranychus kanzawai kishida), Aculops pelekassi, and the like have acquired resistance, to some degree, against almost all existing pesticidal agents. Therefore, in order to prevent and control the damage caused by spider mites, development of a new insecticidal and miticidal agent which shows a high effect against spider mites which have acquired resistance against the conventional miticidal agents is highly desirable.
However, to obtain an insecticidal and miticidal composition which shows no cross-resistance with existing insecticidal and miticidal agents, has no toxicity problems and has little negative impact on the environment, is extremely difficult. Therefore, a means to delay or prevent the development of resistant strains of pest species is always being sought. In order to apply an effective agent as long as possible, a rotational application of agents with different mechanisms of action is adopted for good pest management practice. However, this approach does not necessarily give satisfactory pest control. Therefore, after a resistance problem has occurred, a countermeasure to resistance by combining insecticidal and miticidal agents has been studied. However, a high synergistic action has not always been found.
Therefore, it is an object of this invention to provide an insecticidal and miticidal composition which demonstrates a high controlling effect even against spider mites which have acquired resistance against chlorfenapyr.